* Change stage view and use newly reducedUImainToolbarButtons config to show different custom buttons as main toolbar buttons for when web is in reduced UI.
Currently the clientWidth is not representing the window width but it is representing the available video space width since we are subtracting the width of the participants pane and chat area.
- on iOS safari and chrome, in case we show eg a spinner until we get the videoConferenceJoined event, all `clientResize` are done with size 0 for width/height
- on iOS we never get a `clientResize` call with correct values, except if we force a call by eg opening/closing the chat window
